Most of Belgium Placed Under Orange Heat Alert as Temperatures Near 37°C Before Storms
Belgium's Royal Meteorological Institute has placed the majority of the country under an orange alert as temperatures climb toward 37°C, with thunderstorms expected to break the heat, according to Le Soir.
Near-37°C heat followed by thunderstorms poses direct risks to health and safety across most of Belgium — heat stress for vulnerable groups during the peak, then sudden downpours, gusts and lightning as the storms break. Because the orange alert covers the majority of the country, the disruption is nationwide rather than local, affecting daily plans, outdoor work and travel.
Belgium's Royal Meteorological Institute (IRM in French, KMI in Dutch) issues colour-coded weather warnings — yellow, orange and red — for hazards including heat, storms, rain and wind. An orange alert is the second-highest tier, signalling dangerous conditions likely to disrupt normal activity. In this case the institute placed most of the country under orange as temperatures approached 37°C ahead of an incoming line of thunderstorms.
Background
Belgium has recorded a run of intense summer heat episodes in recent years, with the national record temperature set during the July 2019 heatwave. Meteorologists across Europe have documented that heatwaves in the Low Countries are becoming more frequent and more severe, and that such spells increasingly end in abrupt, storm-driven breaks rather than a gradual cooling.
What to do
Check IRM live bulletins before travelling, secure loose outdoor items ahead of the gusts, stay hydrated and avoid prolonged exposure during the heat peak, and follow guidance for vulnerable people until the storms clear.
Impact
Regional — The alert spans most of Belgium rather than a single region, so Flanders, Wallonia and the Brussels-Capital Region are all exposed. Dense urban areas such as Brussels retain heat overnight, intensifying discomfort, while low-lying and poorly drained districts face the greatest risk of localised flooding when the storms arrive.
Sources & evidence
- View sourceLe SoirPrimary· lesoir.beRetrieved 4 August 2026
- View sourceRoyal Meteorological Institute of Belgium (IRM/KMI)· meteo.beRetrieved 4 August 2026
